2016-04-02 16:35:38

by Joachim Eastwood

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Subject: [PATCH v2 0/2] PINT irqchip driver for NXP LPC18xx family

The LPC1850 has no less than 3 GPIO interrupt blocks. One of these
blocks is called 'gpio pin interrupt' or just PINT. LPC1850 PINT can
handle up to 8 interrupts and these have a one-to-one relationship with
the main interrupt controller (NVIC).

The interrupts on PINT can be either level or edge trigger and supports
any polarity. This patch set adds a irqchip driver for PINT on LPC18xx.

This version address the comments from Thomas and Rob.

Changes since v1:
- use irq_gc_ack_set_bit for edge ack
- switch to generic functions on level mask/unmask
- use revmap to look up hwirq in handler
- describe the interrupts property better in dt doc

Joachim Eastwood (2):
irqchip: add lpc18xx gpio pin interrupt driver
devicetree: document NXP LPC1850 PINT irq controller binding

.../interrupt-controller/nxp,lpc1850-gpio-pint.txt | 26 +++
drivers/irqchip/Kconfig | 5 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-lpc18xx-gpio-pint.c | 219 +++++++++++++++++++++
4 files changed, 251 insertions(+)
create mode 100644 Documentation/devicetree/bindings/interrupt-controller/nxp,lpc1850-gpio-pint.txt
create mode 100644 drivers/irqchip/irq-lpc18xx-gpio-pint.c

--
2.8.0


2016-04-02 16:35:44

by Joachim Eastwood

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Subject: [PATCH v2 2/2] devicetree: document NXP LPC1850 PINT irq controller binding

Add binding documentation for NXP LPC1850 GPIO Pin Interrupt (PINT)
controller.

Signed-off-by: Joachim Eastwood <[email protected]>
---
.../interrupt-controller/nxp,lpc1850-gpio-pint.txt | 26 ++++++++++++++++++++++
1 file changed, 26 insertions(+)
create mode 100644 Documentation/devicetree/bindings/interrupt-controller/nxp,lpc1850-gpio-pint.txt

diff --git a/Documentation/devicetree/bindings/interrupt-controller/nxp,lpc1850-gpio-pint.txt b/Documentation/devicetree/bindings/interrupt-controller/nxp,lpc1850-gpio-pint.txt
new file mode 100644
index 0000000..0d59d31
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/nxp,lpc1850-gpio-pint.txt
@@ -0,0 +1,26 @@
+NXP LPC18xx/43xx GPIO Pin Interrupt (PINT) controller
+
+Required properties:
+
+- compatible : should be "nxp,lpc1850-gpio-pint".
+- reg : Specifies base physical address and size of the registers.
+- interrupt-controller : Identifies the node as an interrupt controller
+- #interrupt-cells : Specifies the number of cells needed to encode an
+ interrupt source. The value shall be 2.
+- interrupts : Must contain the interrupt numbers from the parent controller.
+ This defines the mapping between the controllers where the first
+ interrupt is mapped to pint hwirq 0 and so on. Which interrupts
+ that are connected to where and the number of is device specific.
+ For lpc1850 the mapping is 32 33 34 35 36 37 38 39 (8 in total).
+- clocks: Must contain a reference to the functional clock.
+
+Example:
+
+pint: interrupt-controller@40087000 {
+ compatible = "nxp,lpc1850-gpio-pint";
+ reg = <0x40087000 0x1000>;
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ interrupts = <32 33 34 35 36 37 38 39>;
+ clocks = <&ccu1 CLK_CPU_GPIO>;
+};
--
2.8.0

2016-04-02 16:36:09

by Joachim Eastwood

[permalink] [raw]
Subject: [PATCH v2 1/2] irqchip: add lpc18xx gpio pin interrupt driver

Signed-off-by: Joachim Eastwood <[email protected]>
---
drivers/irqchip/Kconfig | 5 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-lpc18xx-gpio-pint.c | 219 ++++++++++++++++++++++++++++++++
3 files changed, 225 insertions(+)
create mode 100644 drivers/irqchip/irq-lpc18xx-gpio-pint.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 3e12479..0278837e 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -211,6 +211,11 @@ config KEYSTONE_IRQ
Support for Texas Instruments Keystone 2 IRQ controller IP which
is part of the Keystone 2 IPC mechanism

+config LPC18XX_GPIO_PINT
+ bool
+ select IRQ_DOMAIN
+ select GENERIC_IRQ_CHIP
+
config MIPS_GIC
bool
select GENERIC_IRQ_IPI
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index b03cfcb..bf60e0c 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -55,6 +55,7 @@ obj-$(CONFIG_BCM7038_L1_IRQ) += irq-bcm7038-l1.o
obj-$(CONFIG_BCM7120_L2_IRQ) += irq-bcm7120-l2.o
obj-$(CONFIG_BRCMSTB_L2_IRQ) += irq-brcmstb-l2.o
obj-$(CONFIG_KEYSTONE_IRQ) += irq-keystone.o
+obj-$(CONFIG_LPC18XX_GPIO_PINT) += irq-lpc18xx-gpio-pint.o
obj-$(CONFIG_MIPS_GIC) += irq-mips-gic.o
obj-$(CONFIG_ARCH_MEDIATEK) += irq-mtk-sysirq.o
obj-$(CONFIG_ARCH_DIGICOLOR) += irq-digicolor.o
diff --git a/drivers/irqchip/irq-lpc18xx-gpio-pint.c b/drivers/irqchip/irq-lpc18xx-gpio-pint.c
new file mode 100644
index 0000000..d53e99b
--- /dev/null
+++ b/drivers/irqchip/irq-lpc18xx-gpio-pint.c
@@ -0,0 +1,219 @@
+/*
+ * Irqchip driver for GPIO Pin Interrupt (PINT) on NXP LPC18xx/43xx.
+ *
+ * Copyright (C) 2016 Joachim Eastwood <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+
+/* LPC18xx GPIO pin interrupt register offsets */
+#define LPC18XX_GPIO_PINT_ISEL 0x000
+#define LPC18XX_GPIO_PINT_SIENR 0x008
+#define LPC18XX_GPIO_PINT_CIENR 0x00c
+#define LPC18XX_GPIO_PINT_SIENF 0x014
+#define LPC18XX_GPIO_PINT_CIENF 0x018
+#define LPC18XX_GPIO_PINT_IST 0x024
+
+#define PINT_MAX_IRQS 32
+
+struct lpc18xx_gpio_pint_chip {
+ struct irq_domain *domain;
+ void __iomem *base;
+ struct clk *clk;
+ unsigned int revmap[];
+};
+
+static void lpc18xx_gpio_pint_handler(struct irq_desc *desc)
+{
+ struct lpc18xx_gpio_pint_chip *pint = irq_desc_get_handler_data(desc);
+ unsigned int irq = irq_desc_get_irq(desc);
+ unsigned int hwirq = pint->revmap[irq];
+ unsigned int virq;
+
+ virq = irq_find_mapping(pint->domain, hwirq);
+ generic_handle_irq(virq);
+}
+
+static void lpc18xx_gpio_pint_edge_mask(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ u32 mask = d->mask;
+
+ irq_gc_lock(gc);
+ irq_reg_writel(gc, mask, LPC18XX_GPIO_PINT_CIENR);
+ irq_reg_writel(gc, mask, LPC18XX_GPIO_PINT_CIENF);
+ irq_gc_unlock(gc);
+}
+
+static void lpc18xx_gpio_pint_edge_unmask(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ u32 type, mask = d->mask;
+
+ irq_gc_lock(gc);
+ type = irqd_get_trigger_type(d);
+ if (type & IRQ_TYPE_EDGE_RISING)
+ irq_reg_writel(gc, mask, LPC18XX_GPIO_PINT_SIENR);
+ if (type & IRQ_TYPE_EDGE_FALLING)
+ irq_reg_writel(gc, mask, LPC18XX_GPIO_PINT_SIENF);
+ irq_gc_unlock(gc);
+}
+
+static int lpc18xx_gpio_pint_type(struct irq_data *data, unsigned int type)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
+ u32 mask = data->mask;
+
+ irq_gc_lock(gc);
+ if (type & IRQ_TYPE_LEVEL_MASK)
+ gc->type_cache |= mask;
+ else
+ gc->type_cache &= ~mask;
+ irq_reg_writel(gc, gc->type_cache, LPC18XX_GPIO_PINT_ISEL);
+
+ switch (type) {
+ case IRQ_TYPE_LEVEL_HIGH:
+ irq_reg_writel(gc, mask, LPC18XX_GPIO_PINT_SIENF);
+ break;
+
+ case IRQ_TYPE_LEVEL_LOW:
+ irq_reg_writel(gc, mask, LPC18XX_GPIO_PINT_CIENF);
+ break;
+
+ /* IRQ_TYPE_EDGE_* is set in lpc18xx_gpio_pint_edge_unmask */
+ }
+
+ irqd_set_trigger_type(data, type);
+ irq_setup_alt_chip(data, type);
+ irq_gc_unlock(gc);
+
+ return 0;
+}
+
+static int lpc18xx_gpio_pint_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct lpc18xx_gpio_pint_chip *pint;
+ struct irq_chip_generic *gc;
+ int irqs[PINT_MAX_IRQS];
+ unsigned int max_virqno;
+ struct resource *regs;
+ int nrirqs;
+ int i, ret;
+
+ nrirqs = of_irq_count(np);
+ if (nrirqs > PINT_MAX_IRQS)
+ return -EINVAL;
+
+ max_virqno = 0;
+ for (i = 0; i < nrirqs; i++) {
+ irqs[i] = platform_get_irq(pdev, i);
+ if (max_virqno < irqs[i])
+ max_virqno = irqs[i];
+ }
+
+ pint = devm_kzalloc(&pdev->dev,
+ sizeof(*pint) + (sizeof(unsigned int) * max_virqno),
+ GFP_KERNEL);
+ if (!pint)
+ return -ENOMEM;
+
+ regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ pint->base = devm_ioremap_resource(&pdev->dev, regs);
+ if (IS_ERR(pint->base))
+ return PTR_ERR(pint->base);
+
+
+ pint->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(pint->clk)) {
+ dev_err(&pdev->dev, "input clock not found\n");
+ return PTR_ERR(pint->clk);
+ }
+
+ ret = clk_prepare_enable(pint->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to enable clock\n");
+ return ret;
+ }
+
+ pint->domain = irq_domain_add_linear(np, nrirqs, &irq_generic_chip_ops,
+ pint);
+ if (!pint->domain) {
+ dev_err(&pdev->dev, "unable setup irq domain\n");
+ ret = -EINVAL;
+ goto err_domain_add;
+ }
+
+ ret = irq_alloc_domain_generic_chips(pint->domain, nrirqs, 2,
+ "gpio_pint", handle_edge_irq,
+ 0, 0, 0);
+ if (ret) {
+ dev_err(&pdev->dev, "unable alloc irq domain chips\n");
+ goto err_alloc_domain_gc;
+ }
+
+ gc = irq_get_domain_generic_chip(pint->domain, 0);
+ gc->reg_base = pint->base;
+
+ gc->chip_types[0].type = IRQ_TYPE_EDGE_BOTH;
+ gc->chip_types[0].handler = handle_edge_irq;
+ gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
+ gc->chip_types[0].chip.irq_mask = lpc18xx_gpio_pint_edge_mask;
+ gc->chip_types[0].chip.irq_unmask = lpc18xx_gpio_pint_edge_unmask;
+ gc->chip_types[0].chip.irq_set_type = lpc18xx_gpio_pint_type;
+ gc->chip_types[0].regs.ack = LPC18XX_GPIO_PINT_IST;
+
+ gc->chip_types[1].type = IRQ_TYPE_LEVEL_MASK;
+ gc->chip_types[1].handler = handle_level_irq;
+ gc->chip_types[1].chip.irq_mask = irq_gc_mask_disable_reg;
+ gc->chip_types[1].chip.irq_unmask = irq_gc_unmask_enable_reg;
+ gc->chip_types[1].chip.irq_set_type = lpc18xx_gpio_pint_type;
+ gc->chip_types[1].regs.enable = LPC18XX_GPIO_PINT_SIENR;
+ gc->chip_types[1].regs.disable = LPC18XX_GPIO_PINT_CIENR;
+
+ /* Disable and clear all interrupts */
+ writel(~0, pint->base + LPC18XX_GPIO_PINT_CIENR);
+ writel(~0, pint->base + LPC18XX_GPIO_PINT_CIENF);
+ writel(0, pint->base + LPC18XX_GPIO_PINT_ISEL);
+ writel(~0, pint->base + LPC18XX_GPIO_PINT_IST);
+
+ for (i = 0; i < nrirqs; i++) {
+ pint->revmap[irqs[i]] = i;
+ irq_set_chained_handler_and_data(irqs[i],
+ lpc18xx_gpio_pint_handler,
+ pint);
+ }
+
+ return 0;
+
+err_alloc_domain_gc:
+ irq_domain_remove(pint->domain);
+err_domain_add:
+ clk_disable_unprepare(pint->clk);
+ return ret;
+}
+
+static const struct of_device_id lpc18xx_gpio_pint_match[] = {
+ { .compatible = "nxp,lpc1850-gpio-pint" },
+ { }
+};
+
+static struct platform_driver lpc18xx_gpio_pint_driver = {
+ .probe = lpc18xx_gpio_pint_probe,
+ .driver = {
+ .name = "lpc18xx-gpio-pint",
+ .of_match_table = lpc18xx_gpio_pint_match,
+ },
+};
+builtin_platform_driver(lpc18xx_gpio_pint_driver);
--
2.8.0

2016-04-07 17:57:32

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] devicetree: document NXP LPC1850 PINT irq controller binding

On Sat, Apr 02, 2016 at 06:35:24PM +0200, Joachim Eastwood wrote:
> Add binding documentation for NXP LPC1850 GPIO Pin Interrupt (PINT)
> controller.
>
> Signed-off-by: Joachim Eastwood <[email protected]>
> ---
> .../interrupt-controller/nxp,lpc1850-gpio-pint.txt | 26 ++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/interrupt-controller/nxp,lpc1850-gpio-pint.txt

Acked-by: Rob Herring <[email protected]>

2016-04-11 15:15:22

by Marc Zyngier

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] irqchip: add lpc18xx gpio pin interrupt driver

Hi Joachim,

On 02/04/16 17:35, Joachim Eastwood wrote:
> Signed-off-by: Joachim Eastwood <[email protected]>

As a start, a commit message would be appreciated.

> ---
> drivers/irqchip/Kconfig | 5 +
> drivers/irqchip/Makefile | 1 +
> drivers/irqchip/irq-lpc18xx-gpio-pint.c | 219 ++++++++++++++++++++++++++++++++
> 3 files changed, 225 insertions(+)
> create mode 100644 drivers/irqchip/irq-lpc18xx-gpio-pint.c
>
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index 3e12479..0278837e 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -211,6 +211,11 @@ config KEYSTONE_IRQ
> Support for Texas Instruments Keystone 2 IRQ controller IP which
> is part of the Keystone 2 IPC mechanism
>
> +config LPC18XX_GPIO_PINT
> + bool
> + select IRQ_DOMAIN
> + select GENERIC_IRQ_CHIP
> +
> config MIPS_GIC
> bool
> select GENERIC_IRQ_IPI
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index b03cfcb..bf60e0c 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -55,6 +55,7 @@ obj-$(CONFIG_BCM7038_L1_IRQ) += irq-bcm7038-l1.o
> obj-$(CONFIG_BCM7120_L2_IRQ) += irq-bcm7120-l2.o
> obj-$(CONFIG_BRCMSTB_L2_IRQ) += irq-brcmstb-l2.o
> obj-$(CONFIG_KEYSTONE_IRQ) += irq-keystone.o
> +obj-$(CONFIG_LPC18XX_GPIO_PINT) += irq-lpc18xx-gpio-pint.o
> obj-$(CONFIG_MIPS_GIC) += irq-mips-gic.o
> obj-$(CONFIG_ARCH_MEDIATEK) += irq-mtk-sysirq.o
> obj-$(CONFIG_ARCH_DIGICOLOR) += irq-digicolor.o
> diff --git a/drivers/irqchip/irq-lpc18xx-gpio-pint.c b/drivers/irqchip/irq-lpc18xx-gpio-pint.c
> new file mode 100644
> index 0000000..d53e99b
> --- /dev/null
> +++ b/drivers/irqchip/irq-lpc18xx-gpio-pint.c
> @@ -0,0 +1,219 @@
> +/*
> + * Irqchip driver for GPIO Pin Interrupt (PINT) on NXP LPC18xx/43xx.
> + *
> + * Copyright (C) 2016 Joachim Eastwood <[email protected]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/init.h>
> +#include <linux/irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +#include <linux/platform_device.h>
> +
> +/* LPC18xx GPIO pin interrupt register offsets */
> +#define LPC18XX_GPIO_PINT_ISEL 0x000
> +#define LPC18XX_GPIO_PINT_SIENR 0x008
> +#define LPC18XX_GPIO_PINT_CIENR 0x00c
> +#define LPC18XX_GPIO_PINT_SIENF 0x014
> +#define LPC18XX_GPIO_PINT_CIENF 0x018
> +#define LPC18XX_GPIO_PINT_IST 0x024
> +
> +#define PINT_MAX_IRQS 32
> +
> +struct lpc18xx_gpio_pint_chip {
> + struct irq_domain *domain;
> + void __iomem *base;
> + struct clk *clk;
> + unsigned int revmap[];
> +};
> +
> +static void lpc18xx_gpio_pint_handler(struct irq_desc *desc)
> +{
> + struct lpc18xx_gpio_pint_chip *pint = irq_desc_get_handler_data(desc);
> + unsigned int irq = irq_desc_get_irq(desc);
> + unsigned int hwirq = pint->revmap[irq];
> + unsigned int virq;
> +
> + virq = irq_find_mapping(pint->domain, hwirq);
> + generic_handle_irq(virq);

Two things here:
- It feels a bit weird that you are indirecting everything through a
cascade interrupt. As you have a 1:1 relationship between the PINT
interrupts and their NVIC counterparts, this would be better described
as a hierarchical irqchip (see drivers/irqchip/irq-vf610-mscm-ir.c for
an example)
- If you decide to stick with the current approach, you're then missing
the usual chained_irq_{enter,exit}.

Thanks,

M.
--
Jazz is not dead. It just smells funny...

2016-04-11 15:40:12

by Joachim Eastwood

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] irqchip: add lpc18xx gpio pin interrupt driver

Hi Marc,

On 11 April 2016 at 17:15, Marc Zyngier <[email protected]> wrote:
> Hi Joachim,
>
> On 02/04/16 17:35, Joachim Eastwood wrote:
>> Signed-off-by: Joachim Eastwood <[email protected]>
>
> As a start, a commit message would be appreciated.

Ops! I wonder where that disappeared to. The previous version did have one:
https://www.marc.info/?l=devicetree&m=145643797630859&w=3

I'll add it back in the next version.

>> ---
>> drivers/irqchip/Kconfig | 5 +
>> drivers/irqchip/Makefile | 1 +
>> drivers/irqchip/irq-lpc18xx-gpio-pint.c | 219 ++++++++++++++++++++++++++++++++
>> 3 files changed, 225 insertions(+)
>> create mode 100644 drivers/irqchip/irq-lpc18xx-gpio-pint.c
>>
>> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
>> index 3e12479..0278837e 100644
>> --- a/drivers/irqchip/Kconfig
>> +++ b/drivers/irqchip/Kconfig
>> @@ -211,6 +211,11 @@ config KEYSTONE_IRQ
>> Support for Texas Instruments Keystone 2 IRQ controller IP which
>> is part of the Keystone 2 IPC mechanism
>>
>> +config LPC18XX_GPIO_PINT
>> + bool
>> + select IRQ_DOMAIN
>> + select GENERIC_IRQ_CHIP
>> +
>> config MIPS_GIC
>> bool
>> select GENERIC_IRQ_IPI
>> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
>> index b03cfcb..bf60e0c 100644
>> --- a/drivers/irqchip/Makefile
>> +++ b/drivers/irqchip/Makefile
>> @@ -55,6 +55,7 @@ obj-$(CONFIG_BCM7038_L1_IRQ) += irq-bcm7038-l1.o
>> obj-$(CONFIG_BCM7120_L2_IRQ) += irq-bcm7120-l2.o
>> obj-$(CONFIG_BRCMSTB_L2_IRQ) += irq-brcmstb-l2.o
>> obj-$(CONFIG_KEYSTONE_IRQ) += irq-keystone.o
>> +obj-$(CONFIG_LPC18XX_GPIO_PINT) += irq-lpc18xx-gpio-pint.o
>> obj-$(CONFIG_MIPS_GIC) += irq-mips-gic.o
>> obj-$(CONFIG_ARCH_MEDIATEK) += irq-mtk-sysirq.o
>> obj-$(CONFIG_ARCH_DIGICOLOR) += irq-digicolor.o
>> diff --git a/drivers/irqchip/irq-lpc18xx-gpio-pint.c b/drivers/irqchip/irq-lpc18xx-gpio-pint.c
>> new file mode 100644
>> index 0000000..d53e99b
>> --- /dev/null
>> +++ b/drivers/irqchip/irq-lpc18xx-gpio-pint.c
>> @@ -0,0 +1,219 @@
>> +/*
>> + * Irqchip driver for GPIO Pin Interrupt (PINT) on NXP LPC18xx/43xx.
>> + *
>> + * Copyright (C) 2016 Joachim Eastwood <[email protected]>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/init.h>
>> +#include <linux/irq.h>
>> +#include <linux/irqdomain.h>
>> +#include <linux/of.h>
>> +#include <linux/of_irq.h>
>> +#include <linux/platform_device.h>
>> +
>> +/* LPC18xx GPIO pin interrupt register offsets */
>> +#define LPC18XX_GPIO_PINT_ISEL 0x000
>> +#define LPC18XX_GPIO_PINT_SIENR 0x008
>> +#define LPC18XX_GPIO_PINT_CIENR 0x00c
>> +#define LPC18XX_GPIO_PINT_SIENF 0x014
>> +#define LPC18XX_GPIO_PINT_CIENF 0x018
>> +#define LPC18XX_GPIO_PINT_IST 0x024
>> +
>> +#define PINT_MAX_IRQS 32
>> +
>> +struct lpc18xx_gpio_pint_chip {
>> + struct irq_domain *domain;
>> + void __iomem *base;
>> + struct clk *clk;
>> + unsigned int revmap[];
>> +};
>> +
>> +static void lpc18xx_gpio_pint_handler(struct irq_desc *desc)
>> +{
>> + struct lpc18xx_gpio_pint_chip *pint = irq_desc_get_handler_data(desc);
>> + unsigned int irq = irq_desc_get_irq(desc);
>> + unsigned int hwirq = pint->revmap[irq];
>> + unsigned int virq;
>> +
>> + virq = irq_find_mapping(pint->domain, hwirq);
>> + generic_handle_irq(virq);
>
> Two things here:
> - It feels a bit weird that you are indirecting everything through a
> cascade interrupt. As you have a 1:1 relationship between the PINT
> interrupts and their NVIC counterparts, this would be better described
> as a hierarchical irqchip (see drivers/irqchip/irq-vf610-mscm-ir.c for
> an example)

Okey, I'll have a look at how irq-vf610-mscm-ir handels it.


> - If you decide to stick with the current approach, you're then missing
> the usual chained_irq_{enter,exit}.

Indeed.


Thanks for looking through.


regards,
Joachim Eastwood